1. Field of the Invention
This application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2009-027352 filed in Japan on Feb. 9, 2009, the entire contents of which are herein incorporated by reference.
2. Description of the Related Art
The present invention relates to an image forming apparatus that includes an ion generating function in an apparatus that performs processing to form an image, such as a copy machine, printer, or facsimile apparatus.
Recently, electrophotographic image forming apparatuses capable of image forming, such as copy machines, printers, and facsimile apparatuses, have been developed. These image forming apparatuses perform processing to form an image on a recording paper. That is, in such an image forming apparatus, for example, an electrostatic latent image is formed on the surface of a photosensitive drum, this electrostatic latent image is developed using toner to form a toner image on the surface of the photosensitive drum, the toner image is transferred from the photosensitive drum to a recording paper, and heat and pressure are applied to the recording paper to fix the toner image on the recording paper.
In such an image forming apparatus, a harmful exhaust gas may sometimes be produced during the processing to form an image on the recording paper. A main component of this exhaust gas is known to be longifolene or the like generated from the recording paper.
However, image forming apparatuses are indispensible office automation devices in offices and the like, and therefore are installed in nearly all offices, and are furthermore spreading to homes and hospitals. Therefore, harmful exhaust gas discharged from an image forming apparatus causes discomfort to many users.
Consequently, there have been various proposals for achieving purification of such harmful exhaust gas in an image forming apparatus (for example, see JP 2005-4144A, referred to below as Patent Document 1). Patent Document 1 discloses an image forming apparatus in which an air-blowing fan, a minus-ion generating unit, a positively charged filter, and so forth are provided within the image forming apparatus. In this image forming apparatus, toner particles and dust generated within the apparatus are negatively charged, and the negatively charged toner particles and dust are attracted to the positively charged filter, thus reducing the amount of harmful substances emitted outside of the apparatus.
On the other hand, air cleaning devices that purify air within a room have become widespread in offices, homes, hospitals, and the like, and there are various such air cleaning devices (for example, see JP 2002-58731A, referred to below as Patent Document 2). The air cleaning device disclosed in Patent Document 2 simultaneously generates positive and negative ions, and airborne bacteria in the air is effectively removed by the positive and negative ions.
However, with the image forming apparatus disclosed in Patent Document 1, it is necessary to provide the minus-ion generating unit and the positively charged filter, which are not directly necessary for the image forming function of this image forming apparatus, within the image forming apparatus, causing increased size and cost of the image forming apparatus.
Also, with the air cleaning device disclosed in Patent Document 2, even if the air within a room can be purified, the main focus of this air cleaning device is not purification of harmful exhaust gas discharged from the image forming apparatus.
Moreover, it is expensive to provide both a costly image forming apparatus as disclosed in Patent Document 1 and an air cleaning device as disclosed in Patent Document 2.
Therefore, there have been demands for an image forming apparatus whereby it possible to suppress the discharge of harmful exhaust gas as described above by purifying the exhaust gas in the image forming apparatus, and also possible to purify the air of the room in which the image forming apparatus is installed, so that it is not necessary to install an air cleaning device in the room in which the image forming apparatus is installed.